Start by a wall. It is easier to start with a head stand. Put your hands on the floor then your head and work into it by putting your knees on your elbows. Then when you have enough core strength take your knees off and keep them bent in front of you. Then slowly lift them up.

Have someone hold your legs and tell them to keep letting go and to just catch you when you start to fall. Like kinda tapping your legs in a way, if that makes sense. If not, I can explain it better if you want.